Electric heating unit



Filed Aug. 14, 1950 2 Sheets-Sheet 1 .a 5 ma my Tu N m vy MT N T .6 A W lmwy ELECTRIC HEATING UNIT Filed Aug. 14, 1930 2 Sheets-Sheet 2 {NVENTLR loa Xlucaa ATTORNEYS Patented Aug. 15, 1933 1,922,546 ELECTRIC HEATING UNIT Louis V. Lucia, Rome, N. Y. Copper and Brass Incorpo of Maryland assignor to Revere rated, a Corporation Application August 14, 1930. Serial No. 475,274

6 Claims.

This invention relates to electric percolators, and more particularly to the heating of said percolators.

In the construction of electric percolators, it is customary to provide a well, heated by an electric unit, in which successive portions of the liquid are heated and then discharged through a communicating percolator tube, and in embodying the electric heating unit, it has been the practice to locate the unit and the accompanying well beneath the percolator body containing the liquid to be heate The electric percolators constructed in accordance with this heretofore accepted practice however, are practically invariably subject to the objection of relatively low heat efliciency, .and it is the principal object of my invention to overcome this objection and to provide a percolator which presents a heat efficiency of high degree.

In accordance therewith 1 have found, that the low heat efliciency of the prior percolator constructions is ascribable in a major degree to the heretofore accepted location and construction of the electric heating unit and associated parts,

and that if the heating unit and the well are located substantiallywithin the percolator body proper and are constructed and arranged as described hereinafter, not only is a markedly increased heat efficiency obtained, but a general improvement in the functioning of the percolator results as well.

The manner in which'my invention is carried out will be best understood from the following description, taken in conjunction with the accompanying drawings inwhich Fig. 1 is a vertical cross-section of the device of my invention.

Fig. 2 is a plan view of the m the line 2-2 Fig. 1.

Fig. 3 is a vertical cross-section of a modified storm of said device.

Referring to the drawings and in particular to Fig. 1, reference numeral 4 designates the percolator body, mounted upon e base 5, which body serves as the receptacle for the liquid to be treated. i

A cylindrical heating well 6 is disposed entirely within the receptacle 4 with its bottom '7 adja- 50 cent but spaced above the bottom 8 or'the receptacle. The body portion 9 of the well 6 15 Iormed by the shell 11 or an annular, electric heating unit 12 which encloses the well and heats the liquid contained therein, the combined heating unit and well being supported above the same, taken along bottom 8 by posts 13.

a pair of diametrically opposite As will be noted, the heating unit and the well are contained,

in their entirety. ,within the receptacle 4, and will be entirely immersed in the water or other The detailed 6 is as follows:

The bottom liquid therein.

construction of the heating-well '7 of the well is. formed with an upturned annular rim 14 which defines an inlet opening 15 for the entry oi liquid from the receptacle 4, and forms a seat for a cooperating cupshaped valve 1 The top of the well is closed by a cup-washer or similar closure 17 snugly attached to the body portion 9, and preferably detachably attached, either by fitting, threading, latching or the like,

which closure carries a percolator tube 18 providing the well outlet 19 through which the heated liquid from the well is discharged.

The valve head 16 is detachably connected in any suitable fashion to a stem 20 which reciprocates in the limits the late percolator tube 18 and suitably ral movement of the valve head with respect to the valve seat 14.

The stem 20 is fiat in shape, and as thin as is compatible with giving it suiiicient strength, in order to minimize obstruction to the flow of liquid through theoutlet 1'9 and the percolator least at its upper portion, and a narrow, inwardly projecting shoulder 22 is spun or otherwise formed at the bottom edge of the tube.

This valve and associated well construction is the subject of my copending application Serial No. 475,272 filed Aug. 14, 1930.

The specific construction of the heating unit 12 is as follows:

A wire-wound resistor heating element 23 is disposed within the shell 11 in close proximity to the wall 9 of the well 6. The coils 24 of the heating element are wound around a refractory core 25, and th is assembly is firmly set in cement 26, which is injected under pressure into the shell 11 to completely imbed the assembly and eliminate air spaces.

A closure ring 27 extends across the space between the shell 11 and the cement within dered at one si posts 13 to hold the the shell, and this closure is solde in recesses 28 in the posts, and

I liquid at the other side to the in-turned edge 29 of the shell 11, in order to seal the interior of the shell against the ingress of water from the receptacle 4.

The posts 13 extend through the partition 30, constituted by the bottom wall 8 of the receptacle and the top wall of the base 5, and are re-- tained in position by means of integral-shoulders 31 above the partition and detachable nuts 32 threaded upon the portions projecting therebelow. These posts serve as mountings for insulating sleeves 33 which carry the lead wires 34 and 35 for the heating unit.

A ring plate 36 (Figs. 1 and 2) having a pair of diametrically opposite channel brackets 3'1 and 38, is secured between the nuts 32 and base 5. This ring plate supports a pair of clamping screws 39, 40 which clamp the opposite ends of a.

fuse 41, disposed directly against and diametrically across the partition 30, and insulated therefrom by means of a mica strip 42.

The fuse clamping screws 39, 40 are respectively threaded through sleeves 43, 44 mounted in the channel brackets 37 and 38 respectively, and each sleeve is insulated from its bracket by means of mica washers, 45, 46, one interposed at the upper face of the bracket and the other at the lower.

The electric current for the heating unit is led in at the terminal pin 47, passes through the lead wire 48 to the sleeve 43, thence through'the screw 39, fuse 41, screw 40, and sleeve 44, to the lead wire 34, then through the coils 24 of the heating element 23, and finally through the lead 35 to the other terminal pin 49.

The fuse and associated construction form the subject of a separate application, copending herewith, Serial No. 475,273 filed Aug. 14, 1930.

The operation of the device is as follows:

with the receptacle 4 and the well 6 supplied with the liquid to be heated, the current is turned on and the water in the well is rapidly heated and partially vaporized by the heat supplied from the unit 12.

The pressure thereby created serves to keep the valve head 16 in tight engagement with the seat 14, preventing the escape of the heated liquid through the inlet 15, and forces it to escape upwardly through the open outlet 19 and percolator tube 18.

The pressure in the well will be gradually reduced by reason of the'discharge of the heated d vapor through the percolator tube, and wh it finally reaches a point where it is insumcien to withstand the external pressure upon the valve head 16, exerted by the major body of liquid in receptacle 4, the valveghead will be automatically forced up ardly, oif the seat 14, and afresh portion of liq d will flow into the well for heating.

In Fig. 3 I have shown a modified form of my invention wherein the heating unit 12 is mounted in close proximity to the bottom 8 of receptacle 4, and the well 50 does not extend completely through the unit as does the well 6 of Fig. 1. For the ring shaped closure 33 of Fig.1, a base plate 51 is substituted in this modification and in lieu of the valve construction hereinbefore described, a difierent form is used. In the valve construction of the modification, the inlet openings 52 are located at the same end of the heating well 50 as the percolator tube 53, and a flapper valve 54 of known construction is mounted upon the percolator tube, moving upwardly under pressure within the chamber to close the inlet opening, and downwardly to admit fresh liquid when the pressure is sufflciently reduced.

By the arrangement and construction of the heating unit and associated parts in the manner herein described, the heat efliciency is greatly increased and a general improvement in the functioning of the percolator is noted.

The water. or other liquid in the percolator is heated much more quickly and thoroughly than has been possible with the arrangements used heretofore, radiation losses from the heating unit are practically entirely eliminated, the circulation is vigorous, and the completion of the operation is greatly accelerated.

These improved results-are due in great part to the fact that the heating unit and well are practically entirely immersed in the liquid, with a consequent transmission to the liquid of all of the available heat with no radiation loss.

Moreover, by this substantial immersion of the heating unit in the liquid, its life is greatly prolonged as a result of the attendant rapid withdrawal of heat therefrom and the prevention ofdestructive overheating. This rapid withdrawal of heat is of considerable importance in such electric elements, and particularly so where a high wattage in a small unit is desired, as in thepresent case.

While in the foregoing I have disclosed a preferred embodiment of my invention, it is to be understood that the invention is not limited thereto, but contemplates all such equivalent constructions and arrangements of parts as may fall within the scope of the appended claims.

I claim as my invention; a

1. A percolator which comprises, a main re ceptacle for liquid, a heating unit disposed within said receptacle and adapted for substantial immersion in the liquid in said receptacle, a well adjoining said unit adapted to be heated thereby, 1'15 closure means for said well, andmeans associated with said closure means for periodically admitting liquid to said well from said receptacle.

2. A percolator which comprises, a main receptacle for liquid, a heating unit disposed within saidreceptacle and adapted for substantial immersion in the liquid insaid receptacle, a well adjoining said unit adapted to be heated thereby, closure means for said well, and means associated with said closure means for periodically admitting liquid to said well from said receptacle.

3. A percolator which comprises, a main receptacle for liquid, an annular heating unit disposed within said receptacle and adapted for substantial immersion in the liquid in said receptacle, 1 a cylindrical well interiorly of said annular unit adjoining the inner wall thereof adapted to be heated thereby, closure means for said well, and means associated with said closure means for periodically admitting liquid to said well from said receptacle.

4. A percolator which comprises, a main receptacle for liquid, supporting members mounted in the bottom of said receptacle and extending v a slight distance thereabove, an annular heating unit mounted upon said members disposed for substantial immersion in the liquid in said receptacle, a well disposed interiorly of said unit and extending from top to bottom thereof, an inlet at the bottom of said well above the bottom of said receptacle, an outlet tube at the top of said well, and means for periodically opening and closing said inlet.

5. A percolator which comprises, a main receptacle for liquid, an annular casing disposed accesses within said.reeeptacle for substantial immersion in the liquid in said receptacle and defining a cylindrical central welL. heating means within the casing for heating said well, a member extendingacross the top of said well and connected with said casing to provide a top closure, a percolator tube mounted in said member, an annular rim at the bottom edge of the inner wall of said casing defining an inlet opening at the bottom of said well, and valve means cooperating with said rim to periodically open and close said inlet opening for the replacement of liquid discharged through said percolator tube.

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